Individuals who suffer degenerative disc disease, natural spine deformations, a herniated disc, spine injuries or other spine disorders often require surgery on the affected region to relieve pain and prevent further injury. Such spinal surgeries may involve fixation of two or more adjacent vertebral bodies. For patients with varying degrees of degenerative disc disease and/or nerve compression with associated lower back pain, spinal fusion surgery or lumbar arthrodesis (“fusion”) is commonly used to treat the degenerative disease. Fusion commonly involves distracting and/or decompressing one or more intervertebral spaces, followed by removing any associated facet joints or discs, and then joining or “fusing” two or more adjacent vertebra together. Fusion of vertebral bodies also commonly involves fixation of two or more adjacent vertebrae, which may be accomplished through introduction of rods or plates, and screws or other devices into a vertebral joint to join various portions of a vertebra to a corresponding portion on an adjacent vertebra. Given the complexities of surgical procedures, as well as anatomical variation between patients who receive surgical devices, it is often challenging to provide a device or implant that achieves the needs of a particular patient without completely customizing the device or implant for a single patient.
Many prior art fixation devices suffer from significant disadvantages, such as poor stability, poor flexibility, poor accuracy, difficulty in handling, lack of customized features, inability to combine with other materials, loss of fixation over time, subsidence and other disadvantages. Certain fixation devices also impair visibility and provide little or no ability for the operator to gauge depth or accuracy. These problems and shortcomings are even more noticeable for fixation devices used in surgical settings or which otherwise require precision.
In addition, fixation devices used in surgical settings can also suffer from further shortcomings. For example, pedicle screws are subject to relatively high failure rates, which is often attributed to a failure of the bone-screw interface. Screws for use in surgical settings may also be limited for use in only certain bony anatomies, or with only certain types of drilling apparatus, and may not be suitable for combination with other devices or materials.
Accordingly, there is a need for a fixation device that decreases the mean time for affixing the device to the desired location, enhances depth control, stability and accuracy, and which otherwise overcomes the disadvantages of the prior art. There is also need for a more customized fixation device, such as an orthopedic screw, which includes one or more porous elements or fenestrations to aid in osteo-integration when implanting the fixation device. The fixation device may be additively manufactured using biocompatible materials such that the solid and porous aspects of the device are fused together into a single solid construct, and potentially having the porous elements interdigitated within and around various solid elements of the device.
The prior art also fails to teach a system for creating a customized fixation device based on patient data, such as data derived from a patient's MRI or CT scan. For example, the availability of patient-specific data (for example, a vertebral body) may allow a surgeon to accommodate for subtle variations in the position and orientation of a screw or other fixation device to avoid particular bony anatomy, or irregularities in the positioning and alignment of the adjoining vertebral bodies. As another example, the use of patient data may also assist a surgeon in selecting a desired trajectory for an fixation device so as to avoid, for example, crossing the pedicle wall and violating the spinal canal during a spine-related procedure. The use of patient-specific data permits the surgeon to avoid these types of mistakes and may comprise specific orientation, end-stops/hard stops, or other safety related features to avoid over-torque or over-insertion of the fixation device. This data also permits the surgeon to quickly and efficiently locate and place devices with corresponding patient-contacting surface(s), while ensuring the fixation device is in the appropriate location and orientation.
It would therefore be advantageous to provide a fixation device that significantly reduces, if not eliminates, the shortcoming, problems and risks noted above. Other advantages over the prior art will become known upon review of the Summary and Detailed Description and the appended claims.